... Ethan's point about "females looking for a male to stay around and support them" only applies to very recent human history. Before that it was "fuck as much as you can, a lot of babies die and the group/village raises the ones that survive". The nuclear family model is very very new and I do not feel it will survive.

We were Hunter/Gatherers. The whole group was in charge of caring for the young, not just two parents and their own kids. Also for genetic diversity the females and males would need to mix and match, not stay monogamous. At least this is what I got from evo psych.